An Ocean Blueprint for the 21st Century - California Ocean ...

Although not always caused by human activities, strandings of marine mammals, seaturtles, and other endangered species along the shore can be an invaluable tool to learnmore about the potential causes of mortality in these species. In the late 1980s, NOAAestablished a Marine Mammal Health and Stranding Response Program, in response togrowing concerns about the numbers of dead and dying marine mammals washing up onU.S. shores. Between 1991 and 2004, NOAA documented twenty-eight unusual mortalityevents involving marine mammals in U.S. waters alone. These events have included awide range of species and numerous causative factors including diseases, starvation,toxins from harmful algal blooms, and human interactions. However, the causes of at least25 percent of these events are as yet undetermined. No similar federal program exists forendangered sea turtles. A sustained and appropriately funded response and analysis programcould help NOAA and its partners and volunteers to respond to strandings, identifycauses, and recommend actions to prevent further deaths. A similar program for sea turtlescould also provide valuable information to managers.Increased research into the biological, chemical, and psychological stresses to marinemammal, sea turtles, and other protected species populations will allow for more comprehensive,ecosystem-based management. Furthermore, for activities where interaction withprotected populations is likely and unavoidable, better scientific data will lead to moreeffective permitting procedures.Recommendation 20–8The National Oceanic and Atmospheric Administration and U.S. Department of the Interioragencies should develop an expanded program, coordinated through the National OceanCouncil, to examine and mitigate the effects of human activities on marine mammals andendangered species.The program should focus on two areas:• research, monitoring, and assessment to better understand the basic biology, physiology,life history, and population dynamics of marine mammals, sea turtles, and other endangeredor vulnerable marine species and to understand how disease, contaminants, harmfulalgal blooms, human activities, and other stressors may impact these animals. Animportant goal will be to enhance the capability to respond quickly to strandings andunusual mortality events of marine mammals and sea turtles.• technology and engineering to eliminate or mitigate human impacts on marine mammals,sea turtles, and other endangered species.Effects of Noise on Marine MammalsOne particular area that requires better understanding is the effect of sound on marinemammals. Many marine mammals use sound to communicate, navigate, feed, and sensetheir surroundings. These natural behaviors can be disrupted when other sounds interfere.In the ocean, sound emanates from a variety of sources, both natural, such as storms,volcanic eruptions, and earthquakes, and human-generated, including shipping, scientificand commercial surveys, and commercial and military sonar.Scientists know relatively little about the biological, psychological, and behavioralchanges in marine mammals that are caused by human-generated sound. Activities suchas commercial shipping, construction, geological exploration, and sonar certainly can producenoises intense enough to elicit reactions from marine mammals. However, because ofthe complexity of the biological and physical interactions being studied, and the difficultyof conducting studies on marine mammals, many important questions remain unanswered. 16For example, the scientific community currently understands very little about marinemammal hearing and how these animals react to sound. It is not known whether healthC HAPTER 20: PROTECTING M ARINE M AMMALS AND E NDANGERED M ARINE S PECIES315